Application of Grey Model to Predict Acoustical Properties and Tire/Road Noise on Asphalt Pavement

The effect factors of acoustical properties and tire/road noise, such as cruising speed, vehicle categories, pavement surface type and pavement condition are uncertain. Many of the exiting prediction models for acoustical properties and traffic noise have still application limitations and accuracy problems. Therefore, acoustical properties and tire/road noise measured on laboratory and field test is conducted in this study. The equipments of impedance tube and sound intensity instrument are employed for measurement of sound absorption coefficient and tire/road noise, respectively. The GM (1, 2) with Fourier correction Grey Model (FGM) is introduced to predict normal incidence sound absorption coefficient and tire/road noise. The test results show the thinner porous surface has, the topper peak of sound absorption coefficient has at higher frequency. However, the thicker porous surface tend to lower frequency has more peak frequency than the thinner one. Generally, the maximum tire/road noise occurs between 800 Hz and 1200 Hz. Therefore, using the thin porous surface with high air void contents could be effectively reduction of tire/road noise. The Michelin tire compared to the Dunlop tire that has a 1.2 decibels (dB) differences at 1000 Hz frequency and 80 km/h cruising speed. The absolute mean error (AME) and regression analysis shows the GM (1, 2) with FGM is useful for making predictions of normal incidence sound absorption coefficient and tire/road noise